We will be updating the forum software to discourse v3.0.0 on this coming Friday. It will include some significant changes to visual layout of the site, including a sidebar, chat and notifications. There is likely to be about 10 minutes of downtime for this update.
There will be no changes to groups, categories, permissions, etc.
You can read all of the change details at 3.0.0.beta15: Closing into Discourse 3.0 (with Sidebar, Chat, New Menus and more) - announcements - Discourse Meta